Gmail already displays information at the bottom of the in-box showing the time of the last activity on the account and whether it's still open in another location. But people often don't think to check that information, Will Cathcart, a Gmail product manager, said in an interview on Wednesday.
So Google is taking the extra step of displaying a warning to users in the form of a big banner that says "warning your acct was accessed from..." and which specifies a geographic region where the account was accessed when unusual activity was detected.
"For example, if you always log in from the same country and all of a sudden there is a log in from halfway around the world" that is suspicious, Cathcart said. Or, if the system detects that one particular IP address is accessing numerous accounts and changing passwords for them, that would trigger warnings for affected accounts, he said.
For more on this story, read Gmail to alert users to suspicious activity on CNET News.